user manual

Appendices
January 2009 UDA2182 Universal Dual Analyzer Product Manual 217
Example 1: To determine the check resistor value needed to simulate conductivity
measurement of 10
μS, use cell constant 0.1 and perform the following calculation:
10 k ohms = (0.1) x (1,000,000)
10
Example 2: To determine the check resistor value needed to simulate resistivity
measurement of 10 M ohms, use cell constant 0.01 and perform the following
calculation:
100 K ohms = (0.01) x (10,000,000)
Concentration values
Obtain the appropriate check resistance value from the table below.
Table 15-1 Data for Concentration Range Measurements
Material/Weight % Concentration Simulation Resistance (ohms) @ 25º C
Cell Constant
10 25 50
Hydrochloric Acid (HCl)
0
1
4
242.5
68.9
485.0
137.7
Sulfuric Acid (H2SO4)
0
1
4
215.5
56.0
538.7
140.0
1077.4
280.0
Sodium Chloride (NaCl)
0
1
4
574.1
195.2
1435.1
398.0
2870.3
796.1
Sodium Hydroxide (NaOH)
0
1
4
189.2
54.0
473.0
135.1
946.1
270.1